Research On Adaptive Trajectory Tracking Algorithm For Autonomous Vehicles

Autonomous driving technology is an important development direction of vehicle engineering.Autonomous driving technology has broad application prospects in the fields of transportation,industry and military.In order to realize the trajectory tracking function of autonomous driving vehicles and ensure the stability and safety of the vehicle under different working conditions,vehicle adaptive trajectory tracking algorithm is studied in this paper.The vehicle is analyzed for dynamics and kinematics in this paper.Then vehicle dynamic model is established.Magic formula is used to establish the model vehicle tires.In order to ensure the real-time performance of the algorithm,the model is linearized and discretized to provide a model basis for the vehicle adaptive trajectory tracking algorithm.Considering the driving speed and driving environment,adaptive control technology and model predictive control algorithm are used to design vehicle adaptive trajectory tracking algorithm which based on vehicle dynamics model.MATLAB/Simulink-Car Sim cosimulation is used in this paper.The algorithm is simulated under different vehicle speeds and various working conditions.The co-simulation results show that compared with the trajectory tracking algorithm based on MPC,the adaptive trajectory tracking algorithm has better trajectory tracking performance and robustness.when the vehicle is driving at high speed on rough roads and low adhesion coefficient roads,the trajectory tracking performance of the adaptive trajectory tracking algorithm deteriorates.An improved adaptive trajectory tracking algorithm which considering road factors is designed.Vehicle anti-skidding constraint and anti-rollover constraint are set in the improved algorithm to prevent serious sideslip and rollover during driving.The improved algorithm is simulated in the co-simulation environment.The simulation results show that the improved algorithm has better robustness and adaptability on rough roads and low adhesion coefficients roads.The real-vehicle experiment platform is built.Low-speed vehicle experiments on flat roads is conducted.The experimental results show that the lateral error is less than 0.2m and the maximum calculation time is less than 0.01 s.